Rod antennae which are made of insulating material, for example fiberglass or the like, with a wire wound thereon, are known--see U.S. Pat. No. 2,938,210. The wire is wound over essentially the entire length of the rod. The end of the winding at the upper end of the rod, that is, remote from its socket which is adapted to be secured to a vehicle, for example, is carried through a hole within the rod and electrically connected to a sleeve connector, such as a coaxial connector, fitting against the lower end of the rod. The rod as well as the winding are covered by an insulating material, for example of plastic or the like.
Rod antennae of this type intended for use in the frequency modulation (FM) band should have a length of about 1 meter. For mobile use, as an automobile radio antenna, for example, it is desired to have as short as possible an antenna, for example a length of only about 40 cm. Reducing the antenna length to that extent causes a loss in signal, however, which in the FM band may be between about 14 to 20 dB with respect to a simple rod antenna of about 95 cm length, that is, approaching 1 m.